Clamping and pulling device



Dec. 1, 1970 w. M. HULAK 3,543,373

CLAMPING AND PULLING DEVICE Filed June 6, 1968 l/VVENY'OR Mil/14M M Mud/4% 5 ,4 r ram/5K9 United States Patent O US. Cl. 29200 3 Claims ABSTRACT OF THE DISCLOSURE A device for initiating the removal of an inflatable bag assembly from within a hollow molded article. The device includes a clamp for engaging the stem portion of the bag assembly and a fluid-operated, hollow piston which engages the molded article adjacent the access opening of the article during its power stroke to drive the stem and its inflatable bag partially out of the access opening. The device includes a handle for applying clamping pressure to the stem, and for then actuating the hollow piston for drawing the bag assembly partially out of the access opening so that the assembly can then be completely removed by hand.

BACKGROUND OF THE INVENTION Molding techniques have been set forth in the patents to Randolph Reissue Pat. No. 25,241 and Geringer Pat. 3,137,898, wherein hollow tank structures having outwardly convex end walls are produced by laying up porous, fibrous mats approximately in the shape of the container or tank to be produced and impregnating them with a liquid which is subject to curing or setting by application of a setting agent, such as heat, a catalyst, or both.

These methods contemplate the use of an expandible bag or envelope or other fluid-expandible membrane, which will define the shape of the finished article. According to the method of mold assembly set forth in the Randolph Reissue Pat. No. 25,241, the expandible bag or envelope is positioned within the laid-up form in the mold, and preformed fiber end wall caps are telescoped into each end of the laid-up form. The external mold is closed by clamping to the end of the mold casing rigid casing caps which shape the end walls of the tank formed therein. With the mold and fiber preforms thus assembled, the matting is placed under a suitably moderate pressure by expanding the bag to hold the fiber matting in place against the mold, and then the fiber matting is partially permeated with a thermosetting resin or the like. The bag is subsequently expanded by further inflation to progressively compress the fiber matting in such a manner as to distribute the resin throughout the matting and achieve the desired results of pressure molding, while at the same time avoiding migration of the fibers and destruction of the laid-up fiber mats.

The Geringer patent contemplates the provision of an improved structure for assembling and positioning the upper fiber end cap within the mold casing cap. This is accomplished by a removable core which is adapted to be fitted within the central opening in the fiber end cap before the latter element is telescoped within the laid-up matting. This core includes an axially outwardly extending neck which fits within the central opening of theupper end casing cap of the mold so as to assure that the fiber end cap will always be snugly and symmetrically nested against the inner surface of the casing cap when the mold is assembled.

Geringer also contemplates the provision of a cupshaped member which is adapted to be seated in an inverted position on the core below and nested in the fiber 3,543,373 Patented Dec. 1, 1970 end cap. This cup-shaped member has an outer surface generally conforming to the contour of the inner surface of the finished tank, and has a cross-sectional wall thickness which tapers raidally outwardly to a relatively thin rim so that when the bag is expanded in the region of the central opening therein, it will press the cup-shaped member and, thus, exert a more uniform compressive force on the fiber end cap.

While the method and apparatus set forth in the Geringer patent overcome many of the problems stated in that patent, it has been found that, upon disassemblying the mold apparatus from the molded article, it is difficult to remove the assembly which comprises the bag, the cup-shaped member, and the bag-inflating stem from the interior of the molded article, since the cured resin tends to adhere to and form a joint with the removable core. It is necessary, therefore, to hammer the protruding portion of the bag-inflating stem in order to loosen the removal core. Such hammering may tend to damage the opening in the article and may tend to damage a threaded portione of the stem. Even after the core is loosened in this manner, it is diflicult to pull the bag assembly from the interior of the article, since there is very little clearance between the opening and the assembly as the assembly is being pulled through the opening.

SUMMARY OF THE INVENTION This invention provides a device for initiating the removal of the inflatable bag assembly from within a hollow, molded article. The device is applied to the top of the molded article so that it surrounds the access opening of the article and the bag stem. An actuating handle is provided on the device which, when squeezed, will transmit a radial clamping force to the bag stern and, upon the application of further gripping pressure to the handle, will operate a fluid-actuated piston so that the piston is driven against the molded article to thereby drive the clamped stem and its inflatable bag partially out of the access opening.

The device according to this invention provides an axial pull on the bag stern so that the access opening of the molded article is not damaged by prior stem removal procedures, e.g., non-axial hammering of the stem.

The pulling device according to this invention applies its axial force to break any molded seal between the core and the access opening and initiates the removal of the bag assembly so that the remaining parts of that assembly may be removed easily by hand.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view of a molded article showing a clamping and pulling device according to this invention in place on the top of the article; and

FIG. 2 is an enlarged, cross-sectional view of the device illustrated in FIG. 1.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENT Referring now to the drawing, a bag assembly pulling and removing device 10 is illustrated. Thepulling device 10 is applied to a hollow stem 11 of a bag assembly 12. The bag assembly 12 includes the hollow stem 11, an inflatable, flexible bag or envelope comprising a rubber bag 13, a lightweight metal core 14, and a cup-shaped blank shaping member 15.

As is set forth more fully in the above-identified Geringer patent, a hollow, fiber-reinforced, molded resin article 16 is produced by laying up a cylindrical matting form within a mold casing, telescoping a lower end-forming preformed fibrous blank within the lower end of the cylindrical form, and, in a subassembly step, fitting an,

upper fiber blank or end cap about the core 14 above the blank shaping member 15. When this subassembly has been completed, the bag 13 is placed within the cylindrical matting form and the upper end blank is telescoped into the upper end of the body blank. The mold is then closed by an upper casing cap and the stem 11 and the bag 13 are pulled axially upwardly of the mold so that a neck 16 of the core 14 is seated within an opening in the mold casing cap. A wing nut is then threaded onto a threaded portion 18 of the stem 11 to complete the mold assembly operation.

After the hollow article has been molded in accordance with the teachings of the above-identified patents, the upper end cap may be removed from the mold and the article slid longitudinaly from the casing. Either before or after the tank has been removed from the casing, the bag assembly 12 is removed from the hollow interior of the article 16 through an access opening 19. This removal technique is accomplished by the device in a manner which will now be described.

The device 10 comprises an outer housing or cylinder 20 having an upper end wall 21 into which a hollow tube 22 is threaded. The tube 22 has an upper guide cylinder 23, an outer cylindrical side wall 24, and a lower conical end portion which defines a cam surface 25 which slopes radially inwardly toward the axis of the tube 22.

A hollow cylinder 26 is slidably mounted within the tube 22 and is guided axially by the cylinder 23. The cylinder 26 is provided with a plurality of openings 27 which communicate with longitudinaly extending slots 28 to provide the cylinder 26 with a plurality of resilient gripping fingers 29 at the lower end of the cylinder 26. Each finger 29 has a conical outer surface 30 which slidably cooperates with the cam surface 25 on the tube 22. When downwardly directed axial pressure is applied to the hollow cylinder 26 in a manner which will hereinafter be explained, the cam surface 25 forces the fingers 29 radially inwardly so that a threaded inner portion 31 of each finger 29 grips the threaded portion 18 of the stem 11.

The device 10 also includes an inner cylinder 32 which comprises a hollow piston having an annular piston head 33. The piston head 33 is slidably mounted for axial movement in an annular pressure chamber 34, which is defined by the upper end wall 21 of the outer cylinder 20, the outer cylindrical side wall 24 of the tube 22, an inner cylindrical surface 35 of the outer cylinder 20, and by an annular ring 36 which is threaded into the bottom end of the outer cylinder 20.

As was previously indicated, the device 10 is placed in surrounding relationship with the stem 11 and the access opening 19 so that the stem 11 projects through the fingers 29 and through a top opening 40 in the hollow cylinder 26. In this position, a bottom end 41 of the inner cylinder 32 bears against the article 16. In order to drive the cylinder 26 doumwardly so that the resilient fingers 29 are brought into gripping engagement with the threaded portion 18 of the stem 11, a force-applying ,handle assembly 42 is provided. The handle assembly 42 includes first and second hand grip portions'43 and 44, which are fixed to the outer cylinder 20. A forceapplying link is pivoted at one end to the handle 43 by a pin 46. The other end of the link 45 extends through a slot 47 in the handle 44 and is pivoted to a gripping lever 48 by a pin 49. A short link 50 is pivotally connected to the hand grip portion 44 and to the lever 48 so that the link 45 will be forced downwardly to apply axial pressure to the cylinder 26.

This downward movement of the link 45 drives the cylinder 26 axially downwardly so that the fingers 29 are cammed radially inwardly to engage the threaded portion 1-8 of the stem 11. Further closure of the lever 48 toward the hand grip portion 44 causes a headed screw 51 on the lever 48 to close a switch arm 52 against a contact 53 on the hand grip portion 44, Closure of 4 the switch arm 52 against its contact 53 energizes a solenoid-operated valve 54 to reverse the valve 54 from its illustrated position to a position wherein a port 55 is connected to a source of fluid pressure, such as a pump 56, and wherein a port 57 is connected to a reservoir 58.

Therefore, upon further movement of the lever 48 and after the threaded portion 18 of the stem 11 has been clamped by the fingers 29, fluid pressure is admitted through the port 55 to drive the annular piston head 33 axially downwardly until it butts against an annular spacer within the pressure chamber 34. The bottom end 41 of the cylinder 32 is driven against the portion of the molded article 16 which surrounds the access opening 19 to thereby pull the stem 11 upwardly to partially remove the bag assembly 12 from the access opening 19.

When the lever 48 is released, the switch arm 52 moves from its contact 53 to thereby reverse the valve 54 to its illustrating position. When the valve 54 is returned to its illustrated position, the port 57 is connected to the pump 56 and the port 55 is connected to the reservoir 58 to return the cylinder 32 to its illustrated position. Releasing the lever 48 also permits the resilient fingers 29 to ride upwardly on the cam surface 25 to thereby release the threaded portion 18 of the stem 11 so that the device 10 may be removed from its clamped position. The remainder of the bag assembly 12 may then be pulled axially out of the access opening 19 by hand.

The invention is not restricted to the lavish imitation of each and every detail set forth above. Obviously, devices may be provided which change, eliminate, or add certain details without departing from the scope of the present invention.

What is claimed is:

1. Apparatus for initiating the removal of an inflatable bag assembly from within a hollow molded article, said bag assembly including a stem for inflating and defiating the bag which projects from an access opening in the molded article, comprising a first cylinder, a tube coaxially mounted within said first cylinder and defining therewith an annular chamber, a second cylinder mounted for axial movement within said annular chamber and having an annular piston head dividing said annular chamber into first and second pressure chambers, a third cylinder slidably mounted within said tube and having resilient fingers for gripping said stem, means defining a cam surface at one end of said tube for forcing said resilient fingers into gripping engagement with said stem upon the application of axial pressure to one end of said third cylinder, means for applying pressure to said one end of said third cylinder, said pressure-applying means including a force-applying link pivoted to said first cylinder, means responsive to further movement of said link after said link has forced said resilient fingers into clamping engagement with said stem to admit fluid pressure to said first pressure chamber and, simultaneously, to exhaust fluid pressure from said second pressure chamber so that one end of said second cylinder is driven into force-applying engagement with said article adjacent said access opening and to thereby drive said resilient fingers and said stem and its inflatable bag partially out of said access opening.

2. Apparatus for initiating the removal of an inflatable bag assembly from within a hollow molded article, said bag assembly including a stem for inflating and defiating the bag which projects from an access opening in the molded article, comprising a first cylinder, a tube coaxially mounted within said first cylinder and defining therewith an annular chamber, a second cylinder mounted for axial movement within said annular chamber, a third cylinder slidably mounted within said tube and having resilient fingers for gripping said stem, means defining a cam surface at one end of said tube for forcing said resilient fingers into gripping engagement with said stem upon the application of axial pressure to one end of said third cylinder, means for applying pressure to said one end of said third cylinder, means responsive to further movement of said pressure-applying means after said pressure-applying means has forced said resilient fingers into clamping engagement with said stem to drive said second cylinder into force-applying engagement with said article adjacent said access opening and to thereby drive said resilient fingers and said stem and its inflatable bag partially out of said access opening.

3. Apparatus according to claim 2, wherein said stem is provided with external threads and wherein the resilient fingers of said clamping means are provided with cooperating threaded portions.

References Cited UNITED STATES PATENTS 1,858,238 5/1932 Cornwell 29264 3,074,156 1/1963 Hinrichsen et a1. 29--262 3,137,060 6/1964 Granzer et a1.

3,359,618 12/1967 Murphy.

THOMAS H. EAGER, Primary Examiner US. Cl. X.R. 29235, 252 

